The idea of creating a material that is mostly air isn't particularly impressive. The technique of actually doing it is where it gets clever, and the technique used here to make this gold foam is not the same as the techniques used to create the familiar aerogels. FTA:

"The method chosen, in which the gold particles are crystallised directly during manufacture of the aerogel protein structure (and not, for example, added to an existing scaffold) is new. The method's biggest advantage is that it makes it easy to obtain a homogeneous gold aerogel, perfectly mimicking gold alloys."

I wonder heavy metal foams would be a good lightweight radiation shield? At first blush you would think it is weight/density dependent but if you have to wonder if radiation aligns itself with the 'holes' between the atoms.

Actually if radiation is aligned with a crystal lattice it interacts even more with the material and the radiation length (the distance travelled before 1/e of the particles interact on average) gets shorter. However this only happens if the radiation is aligned to within a few milli-radians of the symmetry axis of the crystal (and most metal you encounter is not a single crystal). I actually measured this effect as part of my PhD thesis for an application in the main particle physics experiment I was working on.

So no, this material will probably be no more effective than the same mass of gold in a thin, but solid, sheet. Radiation shielding with matter is a statistical affair and the fewer nuclei you have the less shielding you get. I'm also surprised that they suggest a use in jewelry since they also describe it as easily malleable, far more so than solid gold. Still it is interesting.

This stuff is very different from Aerogel. I bought some Aerogel on eBay for my daughter's science project. Aerogel is very rigid and fragile. It can fracture just from normal handling. According to TFA, this gold foam is malleable, and can be bent and shaped by hand. That would make it very different from old fashioned Aerogel, and suitable for different applications. Supposedly, Aerographene [wikipedia.org] is also elastic.

The implications for the hip-hop and gold-tooth industries are staggering, as suddenly bling is no longer confined to being gold, but can be other non-gold colors.

People have been saying for years that gold should come in other colors, as gold was just too damned boring.

When asked if creating non-gold gold would create confusion among buyers of gold, as well as creating higher change of fraud due to non-gold-gold gold being produced to be represented as non-gold gold, representatives declined comment citing they were not authorized to speculate on such drivel.

The first metals known to humans came from meteorites falling to earth, and droplets of mercury that were seen running out of stones as they were heated. So it would have been an easy assumption that heating rocks produces metals.

Not arguing with you, but it's worth noting that pure gold is actually quite easy to bend by hand... while I wouldn't say it's necessarily "soft", it's surprisingly easy to warp the shape of something made of pure gold with just finger pressure without even necessarily trying.

A pound of gold is higher density than a pound of feathers, so it has smaller volume.
If we weigh those two in normal environment, then there's smaller buoyancy force affects on a pound of gold than a pound of feathers.
So, assume that there is no atmosphere, 'a pound' of gold is, now, lighter than 'a pound' of feathers.

Nice feat, but does this also have a practical usage, or is this a purely academic exercise? From the article: 'But in contrast to its conventional form, it is soft and malleable by hand' - so not quite usable for jewelry. Where gold is used for its conductivity, it is mostly used as plating, not as solid or foamy object. So... what am I missing?

From the article: 'But in contrast to its conventional form, it is soft and malleable by hand' - so not quite usable for jewelry

That depends on what sort of jewellery you're using it for.

While I wouldn't claim to be a jeweller, I have probably made more items of jewellery then the other hundred people on this boat, and repaired a number more. I could certainly envisage using, for example, the red form as the centre piece for a pendant, with (say) alternating "rays" of gold and silver sheet (or gold rays la